Our Center's effectiveness will be measured by the ability of the biomedical community to access ontologies, ontology metadata, and ontology-based annotations of biomedical data sets;to develop. new ontology-aware tools and applications;and to incorporate methods that ensure conformance with knowledge-representation standards in the creation of new content. The achievement of these goals depends on a substantial infrastructure to allow access to the Center's services and to support the Center's own research and development activities. The Stanford Center for Biomedical Informatics Research has more than 35 years of experience in the management of wide-ranging computational resources and in providing outstanding infrastructure to support advanced research and development in biomedical informatics. Over the past four years, we have developed a. flexible and scalable infrastructure to host the NCBO resources and to support our collaborators and users, including mechanisms to serve ontology content created by biomedical researchers from around the world. Most of this infrastructure is already adequate to support the projected capacity and scope of the Center. We will build on this infrastructure to provide a new generation of NCBO services and tools, addressing the key challenges of data management, and fast and reliable access to our content.